Method of forming transformer coils



Dec. 14, 1954 w. R. M CARTY 2,696,559

METHOD OF FORMING TRANSFORMER COILS Filed Oct. 13. 1950 2 Sheets-Sheet 11 1 FIG. 2. t2

INVENTOR.

7/ WILLARD R. MCCARTY a M- an" A TORNEY.

United States Patent METHOD OF FORMING TRANSFORMER COILS Willard R.McCarty, Overland, Mo., assignor to Wagner Electric Corporation, St.Louis, Mo., a corporation of Delaware Application October 13, 1950,Serial No. 189,964

3 Claims. (Cl. 29-15557) This invention relates to shell type powertransformers in which the low voltage winding is divided and positionedon opposite sides of the high voltage winding, and is more particularlydirected to a method of winding the coils so that no splices or jointsare required between the sections of the transformer windings.

One of the objects of the invention is to produce transformer windingsof different cross sectional area so that one coil is a continuation ofthe other and which may be nested one within the other.

Another object of the invention is to produce a transformer coil made upof two or more sections without joints between the windings thereon andin a more rapid manner.

A further object of the invention is to produce a sectionalizedtransformer winding using less conductive material than coils wound withjoints or splices therebetween.

Still another object of the invention is to produce sectionalizedtransformer coils in such manner that they may 1 be more rapidly andmore easily insulated one from the other.

The invention consists in winding two or more coils of different crosssectional area in which the windings are continuous and so disposedrelative to each other that they may be nested without the necessity ofusing soldered or other types of joints and which may have sectionalizedinsulation inserted between the coil sections during the nestingoperation.

In the drawings:

Fig. 1 is an end view of a shell type transformer showing the windingsin place,

Fig. 2 is a sectional view taken substantially along the line 22 of Fig.1,

Fig. 3 is a diagrammatic illustration showing the relative position ofthe coils as they are being wound,

Fig. 4 is a view similar to Fig. 3 but with the smaller coil beingrotated at 180,

Fig. 5 is a view similar to Fig. 4 but showing one of the coils inposition for nesting; and

Fig. 6 shows both coils coaxially disposed and nested one within theother.

Referring to Figs. 1 and 2, a complete transformer is disclosed whichconsists of two similar cores 1 through the windows 2 of which is placeda sectionalized high voltage winding 3. Each winding section is wound onan insulating sleeve 4 provided with end insulating elements 5. The highvoltage Winding may be a single coil if so desired. Between theinsulating sleeve 4 and the adjacent legs of cores 1 is a section 6 ofthe low voltage winding which is wound on an insulating sleeve 7provided with end insulating elements 8. Between the high voltagewinding 3 and the outer legs of cores 1 is located a second section ofthe low voltage winding 9 wound on the insulating sleeve 10 providedwith end insulating elements 11.

The low voltage winding of the transformer is made up of two windingsconsisting of a single layer, each winding disposed one on top of theother on each of the sleeves 7 and 10. It is, therefore, necessary thatthere be two connecting leads 12 and 13 between the inner and outersections 6 and 9 of the low voltage windings. The ends 14 and 15 of oneof the low voltage windings are brought out in the manner shown, and theends 16 and 17 of the other winding are also brought out in the mannershown. The ends of the high voltage winding are brought out at 18 and19. The internal leads at the center of the high voltage winding are notshown but would normally come out to a tap changer.

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It is important that connecting leads 12 and 13 between the two sectionsof the low voltage winding have good conductivity and adequateinsulation and not be liable to failure since they are normally placedat the bottom of the transformer tank where they are not readilyavailable for inspection by removal of the tank cover.

The preferred method of winding the two sections of the low voltagewinding wherein there is no joint in the conductor therebetween, isshown in Figs. 3, 4-, 5 and 6. The low voltage coil forms are placed oncoaxial mandrels 20 located adjacent each other with just sufficientaxial dis tance between them to produce the proper length of connectingleads 12 and 13 when the sections of the windlngs are assembled. Theturns of these windings, in the diagrams of Figs. 3 to 6 inclusive, areshown wound side by side instead of one on top of the other, as in theactual transformer construction, in order that the construction may beclearly shown. This representation of the wind- 1ngs does not alter theunique properties of this method and, therefore, transformers may wellbe wound in this manner.

After the sleeves 7 and 10 for the two sections of the windingsaremounted on their respective mandrels 20 in the positions shown in Fig.3, the operator anchors the ends 14 and 15 of the conductors to thesleeve 10 at 21 and 22, then rotates the sleeves in a clockwisedirection on the mandrels 2-0 until the required turns are placedthereon, after which the conductors are anchored to sleeve 10 at 23 and24. The conductors are now carried over to sleeve 7 and anchoredsecurely at 25 and 26. It is to be noted that the conductors are nowcrossed and the carryover action forms the connecting leads 12 and 13.The mandrel is again placed in rotation but in a counterclockwisedirection for reasons to be explained later, and the required number ofturns, usually the same as on sleeve 10, wound thereon. Upon completionof the Winding turns on sleeve 7, the ends are anchored at 27 and 28,after which the conductors are cut to the required length for leads andthe coils then removed from the mandrels.

The sleeves 7 and 19 and their windings 6 and 9 are removed from themandrels 29 after which the sleeve 7 is rotated counter-clockwise abouta line in the plane of the top or lead side of the sleeves shown in Fig.3 to the position shown in Fig. 4. This action places the connectingleads 12 and 13 and sleeve 7 parallel to each other and displacedupwardly from the axis of sleeve 10.

The next operation on the coil assembly is to rotate the sleeve 7downwardly about the edge 29 (Fig. 5) so that the end, including theedges 30, 31, 32 and 33, enters the end of sleeve 10 which includes theedges 34, 35, 36 and 37, as shown in Fig. 5. After placing sleeve 7 inthe position shown in Fig. 5, it is a simple matter to continue themovement of this sleeve to the position shown in Fig. 6, which is thefinal position of sleeve 7 with relation to sleeve 10 in the completedtransformer.

After performing the operation just described, the coils 6 and 9 on thesleeves are circumscribed in the same direction, this being thecondition illustrated in Figures 5 and 6. The total voltage across theterminals of the coils is now the sum of the voltage induced in eachcoil.

Any extra insulation required for the connecting leads 12 and 13 isplaced on these leads in the form of flexible tubes pre-cut to theproper length prior to starting the winding operation and slides alongthe conductors until the turns on sleeve 10 are in place, positioned andanchored as the windings are secured to sleeves 7 and 10 at points 23,24, 25 and 26 for the two conductors. The only difference betweenwinding the coils consisting of the two conductors shown in Figs. 3 to6, inclusive, with the conductors side by side, and as shown in Fig. 2,one conductor being on top of the other, is that in the former theoperator handles two conductors simul taneously, while in the latter thecoils are usually wound consecutively so that any inter-coil insulationdeemed necessary may be inserted. In either case, extra insulation isapplied at the start to the connecting leads and the ends of theconductors placed and anchored in position, as described above.

A modification in producing the above two-coil low voltage windingconsists in making the mandrel set--up exactly as described, but insteadof starting the winding at the end of sleeve opposite sleeve 7, therequired length of conductor for one of thesleeves is unreeled from thesupply reel onto an auxiliary reel, at which time the connecting lead 12of Fig. 3, for example, is anchored at points 23 and 25 on sleeves 10and 7, after which both sleeves are wound simultaneously by rotating themandrel, in the case shown, in a counter-clockwise direction. Thismethod requires more equipment and, due to the necessity of handling apart of the conductor twice. is slower notwithstanding that only half asmany revolutions of the winding machine would be required to produce agiven coil.

Another modification of this method of producing coils is possible whereeither a two-section single layer, single conductor coil, or atwo-conductor side-by-side double coil is to be made. This modificationconsists of winding the conductor or conductors on the smaller of thetwo sleeves and anchoring the same thereto; placing the larger sleeveover the smaller and holding it in place by any desired means so that itcan be driven by the winding machine; anchoring the connecting lead tothe larger sleeve; and finally winding the conductor or conductors onthe larger sleeve in the usual manner. After the low voltage windingshave been wound and assembled, as above described, it is only necessaryto insert the high voltage winding 3 on its sleeve 4 which has beenseparately wound, in the space between the inner and outer sections ofthe low voltage winding and secure it in place; and then assemble thecore iron therewith, as shown in Figs. 1 and 2, to produce the completecore and coils of a transformer.

Other modifications of this invention will be apparent to those skilledin the art and, therefore, the scope of the invention is limited only bythe claims appended hereto.

What I claim is:

1. In winding transformers of the type including a low voltage coil intwo sections, one section being nested within the other with theconnecting conductor portion for the two coil sections beingsubstantially entirely without the low voltage coil, and a high voltagecoil received in the space between the nested low voltage coil sections,the process of winding and nesting the two-section low voltage coil froma pair of continuous conductors so as to obviate wire connections ineach of the conductor portions connecting the coil sections and so as toavoid disposition of the connecting conductor portion between the coilsections, which process comprises anchoring the pair of conductors toone end portion of a sleeve, simultaneously winding the pair ofconductors on the sleeve and anchoring the conductors to the other endportion of the sleeve, crossing the conductors and anchoring the same toan adjacent end portion of a second sleeve having a smaller diameterthan the first mentioned sleeve, simultaneously winding the conductorson the second sleeve in a direction opposite to that on the firstmentioned sleeve, and anchoring the conductors to the other end portionof the second sleeve, rotating the second sleeve about its longitudinalaxis to uncross the conductors and then rotating the second sleeve aboutits transverse axis to insert the last wound end of the second sleeveinto the last wound end of the first mentioned sleeve so as to provide atwo-section, two-conductor nested coil from a pair of continuousconductors with the connecting conductor portions for the two-coilsections being disposed substantially entirely without the resultingnested coil.

2. In winding transformers of the type including a low voltage coil intwo sections, one section being nested Within the other with theconnecting conductor portions for the two coil sections beingsubstantially entirely without the low voltage coil, and a high voltagecoil received in the space between the nested low voltage coil sections,the process of successively winding the twosection low voltage coil froma pair of continuous conductors and nesting the two sections so as toobviate Wire connections in each of the conductor portions connectingthe coil sections and so as to avoid disposition of the connectingconductor portions between the coil sections, which process comprisesanchoring the conductors to one end portion of a sleeve, winding theconductors on the sleeve and anchoring the conductors to the other endportion of the sleeve, crossing the conductors and anchoring the same toan adjacent end portion of a second sleeve having a smaller diameterthan the first mentioned sleeve, Winding the conductors on the secondsleeve in a direction opposite to that on the first mentioned sleeve,and anchoring the conductors to the other end portion of the secondsleeve, rotating the second sleeve about its longitudinal axis touncross the conductors and then rotating the second sleeve about itstransverse axis to insert the last wound end of the second sleeve intothe last wound end of the first mentioned sleeve so as to provide atwo-section, two-conductor nested coil from a pair of continuousconductors with the connecting conductor portions for the two-coilsections being disposed substantially entirely Without the resultingnested coil.

3. In winding transformers of the type including a low voltage coil intwo sections, one section being nested Within the other with theconnecting conductor portion for the two coil sections beingsubstantially entirely without the low voltage coil, and a high voltagecoil received in the space between the nested low voltage coil sections,the process of winding and nesting the twosection low voltage coil froma continuous conductor so as to obviate a Wire connection in theconductor portron connecting the coil sections and so as to avoiddispositions of the connecting conductor portion between the coilsections, which process comprises anchoring the conductor to one endportion of a sleeve, winding the conductor on the sleeve and anchoringthe conductor to the other end portion of the sleeve, anchoring the sameto an adjacent end portion of a second sleeve havmg a smaller diameterthan the first mentioned sleeve, winding the conductor on the secondsleeve in a directron opposite to that on the first mentioned sleeve andanchoring the conductor to the other end portion of the second sleeve,rotating the second sleeve about its longitudinal axis and then rotatingthe second sleeve about its transverse axis to insert the last wound endof the second sleeve into the last Wound end of the first mentionedsleeve so as to provide a two-section, single conductor nested coil froma single continuous conductor with the connecting conductor portion forthe two-coil sections being disposed substantially entirely without theresulting nested coil.

References Qited in the file of this patent UNITED STATES PATENTS NumberName Date 634,198 Buckingham et al Oct. 3, 1899 862,506 Pfanstiehl Aug.6, 1907 892,763 Pfanstiehl July 7, 1908 1,304,184 Iohannesen May 20,1919 1,673,886 Sattels June 9, 1928 1,910,227 Austin May 23, 19331,992,814 Cooney Feb. 26, 1935 2,038,297 Ketcham Apr. 21, 1936 2,246,239Brand June 17, 1941 2,269,678 Maui-er Jan. 13, 1942 2,388,598 CahillNov. 6, 1945 2,400,008 Korte May 7, 1946 2,404,185 Mann July 16, 19462,577,825 Strickland Dec. 11, 1951 2,608,610 Thulin Aug. 26, 1952

